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The unicode property indicates whether or not the "u" flag is used with a regular expression. unicode is a read-only property of an individual regular expression instance.

Property attributes of RegExp.prototype.unicode
Writable no
Enumerable no
Configurable yes


The value of unicode is a Boolean and true if the "u" flag was used; otherwise false. The "u" flag enables various Unicode-related features. With the "u" flag, any Unicode code point escapes will be interpreted as such, for example.

You cannot change this property directly. It is read-only.


Using the unicode property

var regex = new RegExp('\u{61}', 'u');

console.log(regex.unicode); // true


Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'RegExp.prototype.unicode' in that specification.
Standard Initial definition.
ECMAScript Latest Draft (ECMA-262)
The definition of 'RegExp.prototype.unicode' in that specification.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support5012146 No3710
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support Yes50 Yes463710 ?

1. Case folding is implemented in version 13

See also

Document Tags and Contributors

 Contributors to this page: wbamberg, schalkneethling, fscholz, jameshkramer, kdex, valtlai, arai
 Last updated by: wbamberg,